Fault Tree Analysis (FTA), a logical reasoning method for analyzing system reliability and safety raised by H. A. Watson and D. F. Haasl in Bell Laboratories of the United States in the early 1960s, is recognized as one of the simplest, most effective and most promising means for analyzing, forecasting and designing the reliability of complex systems.
It is difficult for a fault tree constructed by a general method to deep into the physics of failure on a component to conduct analysis. While the failure of component includes degenerative failure and transient failure, the information is very important to the reliability design and quality problem loop analysis. The fault tree constructed by a know method cannot go deep into the events of physics of failure of a component, and thus it is difficult to describe the failure mechanism and failure path.